An intelligent substation is a substation having primary and secondary devices of the substation as intelligent objects, and capable of realizing information sharing and interoperation by standardizing intelligent information based on a high-speed network communication platform and also capable of realizing automation functions such as measurement monitoring, control and protection, information management and the like based on network data.
The intelligent substation includes a station level, a bay level and a process level, and effective contact is mainly performed among different levels through optical cables. Each level includes different systems, devices and apparatuses which co-act and are cooperated with one another. The station level needs to record and collect electrical energy and related operating data of the substation in real time and is a platform allowing operators to know an operating state of the intelligent substation all the time. The bay level mainly includes secondary devices such as a measurement and control apparatus or a protection apparatus, and mainly completes measurement, control and protection of the devices on the process level.
In the related art, the substation is divided into a high-voltage line part, a main transformer part and a medium voltage side part. Each part is further divided into different device bays. Because the protection apparatuses are classified according to the device bays divided by functions, a plurality of types of protection apparatuses may exist in each bay of the substation. If N types of protection apparatuses exist at a bay, intelligent terminals and merging units for the bay need to be respectively connected to the protection apparatuses through N lines. Therefore, due to numerous secondary devices on the bay level, floor space of the secondary devices is large, and debugging and maintenance workload is relatively high. Moreover, wiring on the process level is complicated and tedious, and difficulty of construction is high, so that the cost of the whole substation is high.
The intelligent terminals stated above are intelligent assemblies. The intelligent terminals are connected to primary devices, such as a circuit breaker, knife switch and main transformer and the like, through cables, and connected to secondary devices for protecting, measuring and controlling and the like through optical fibers, so as to achieve measurement function, control function and the like over the primary devices. Specifically, the intelligent terminals mainly have the following functions:                receiving control instructions for trip protection and tripping;        receiving and executing opening/closing control instructions from a measuring and control device;        uploading position signals of knife switches;        collecting and uploading temperature data/humidity data.        